Unilateral Single Joint Arthritis Changes Joint Power in Unaffected Joints

Pain and disability associated with arthritis of the hip, knee, or ankle is well-documented. However, data on joint power and how arthritis in one joint affects power in that joint and in unaffected joints are limited. This study asks if arthritis in any one joint leads to (1) loss of power in that affected joint compared to the contralateral, unaffected joint; (2) loss of total power in the affected limb as compared to the contralateral, unaffected limb; and (3) increased power production in the joints of the ipsilateral limb. Ground reaction forces and joint angles during self-selected speed walking were collected from participants with symptomatic, unilateral ankle (N = 183), hip (N = 63), and knee arthritis (N = 20). Bilateral joint power from the hip, knee, and ankle joints as well as total limb power was calculated for the last third of the stance phase. Arthritis in the hip (p < 0.001), knee (p = 0.008), or ankle (p < 0.001) lead to a loss of power at the affected joint and in the affected limb, though the knee on the affected side does offset some of that loss in participants with hip and ankle arthritis (p < 0.001). The contralateral, unaffected limb (p < 0.001), especially the ankle, produces greater power. Clinical Significance: Isolated lower limb joint arthritis leads to a loss of power on the affected side and compensation by contralateral, unaffected joints. Those joints may be subsequently impacted through repetitive loading and could lead to further degeneration without intervention.